Presumably, Kim's comments will be a braggadocio reaction to President Trump and General Mattis' comments (begins around 6:30):

Mattis warned "[North Korea] R&D is accelerating and they now appear to have the capability to launch an ICBM attack on anywhere in the world" to which Trump replied "we will take care of it... it is a situation we will handle."

Trump then tweeted later this evening: "After North Korea missile launch, it's more important than ever to fund our gov't & military! "

North Korea announces that it “successfully” fired a new Hwasong-15 missile with improved technology, according to an announcement read on state-run television on Wednesday.

Kim gave the order to test fire the missile, state-run Korean Central News Agency said.

“After watching the successful launch of the new type ICBM Hwasong-15, Kim Jong Un declared with pride that now we have finally realized the great historic cause of completing the state nuclear force, the cause of building a rocket power,” KCNA said.

The new missile "brings the whole US mainland within North Korea's range."